Quantum dot film

ABSTRACT

A quantum dot film includes a plurality of sealed microcells. The microcells may be formed within a layer of polymeric material and sealed with a sealing material. Also, the microcells may contain a dispersion of a solvent and a plurality of quantum dots. A method of making a quantum dot film includes providing a layer of polymeric material having a plurality of open microcells, filling the plurality of open microcells with a dispersion of a solvent and plurality of quantum dots, and sealing the microcells.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to and claims priority of U.S. ProvisionalApplication 62/568,909 filed on Oct. 6, 2017. The entire disclosure ofthe aforementioned application is herein incorporated by reference.

FIELD OF THE INVENTION

This invention relates to quantum dot films. More specifically, in oneaspect this invention relates to display systems comprising quantum dotfilms. In another aspect, this invention relates to a method of makingquantum dot films.

BACKGROUND

Quantum dots are particles made from nanomaterials that emit light ofspecific frequencies upon the application of an electrical current orlight. The frequencies of the light emitted by the quantum dots may bevaried by changing the dots' size, shape, and type of material. Oneapplication of quantum dots are electro-optic displays, specifically,LED displays, because of the potential for improved color accuracy.

The term “electro-optic”, as applied to a material or a display, is usedherein in its conventional meaning in the imaging art to refer to amaterial having first and second display states differing in at leastone optical property, the material being changed from its first to itssecond display state by application of an electric field to thematerial. Although the optical property is typically color perceptibleto the human eye, it may be another optical property, such as opticaltransmission, reflectance, luminescence, or in the case of displaysintended for machine reading, pseudo-color in the sense of a change inreflectance of electromagnetic wavelengths outside the visible range.

Quantum dots are commonly incorporated into an LED display by beingprovided in the form of a film that is laminated between a back-lightunit and a red-green-blue (RGB) color filter. The back-light unitcomprises a blue LED and a portion of the emitted blue light isconverted into red and green light after passing through the quantum dotfilm. Therefore, the light exiting the quantum dot film and entering thecolor filter includes a substantially increased portion of red, green,or blue light. As a result, the amount of light that is absorbed by thecolor filter is reduced.

Quantum dot films are manufactured by blending quantum dots in apolymer, such as an epoxy, and applying a barrier layer on either sideof the layer of polymer-quantum dot blend. The cured polymer and barrierlayers seal the quantum dots from oxygen and water, which may degradethe material over time. However, there are frequently difficultiesinherent in mixing quantum dots and polymers, such as homogeneity,dispersibility, and performance loss (quantum yield and reliability).Thus, there is a need for improved quantum dot films.

SUMMARY

According to a first embodiment of the present invention, a quantum dotfilm may comprise a plurality of sealed microcells. The microcells maybe formed within a layer of polymeric material and sealed with a sealingmaterial. Also, the microcells may contain a dispersion comprising asolvent and a plurality of quantum dots.

According to a second embodiment of the present invention, a method ofmaking a quantum dot film may comprise providing a layer of polymericmaterial having a plurality of open microcells, filling the plurality ofopen microcells with a dispersion comprising a solvent and a pluralityof quantum dots, and sealing the microcells.

These and other aspects of the present invention will be apparent inview of the following description.

BRIEF DESCRIPTION OF THE FIGURES

The drawing Figures depict one or more implementations in accord withthe present concepts, by way of example only, not by way of limitations.In the figures, like reference numerals refer to the same or similarelements.

FIG. 1 is a side cross-sectional view of a quantum dot film according toa first embodiment of the present invention.

FIG. 2 is a side cross-sectional view of a display incorporating aquantum dot film according to an embodiment of the present invention.

FIGS. 1 and 2 are schematic drawings that are not drawn to scale forease of understanding of the various embodiments of the invention.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant teachings. However, it should be apparent to those skilledin the art that the present teachings may be practiced without suchdetails.

Generally, the various embodiments of the present invention provide animproved quantum dot film by eliminating the polymer/quantum dot blends.The films according to various embodiments of the present inventionencapsulate the quantum dot film in a plurality of sealed microcells.The dispersions of quantum dots may be encapsulated in optical filmsusing various methods. For example, materials incorporated in displaysystems have been described in numerous patents and applicationsassigned to or in the names of the Massachusetts Institute of Technology(MIT), E Ink Corporation, E Ink California, LLC, and related companies.The various technologies use encapsulated and microcell electrophoreticand other electro-optic media. The technologies described in thesepatents and applications, the entireties of which are incorporated byreference herein, include:

(a) Electrophoretic particles, fluids and fluid additives; see forexample U.S. Pat. Nos. 7,002,728 and 7,679,814;

(b) Capsules, binders and encapsulation processes; see for example U.S.Pat. Nos. 6,922,276 and 7,411,719;

(c) Microcell structures, wall materials, and methods of formingmicrocells; see for example U.S. Pat. Nos. 6,672,921; 6,751,007;6,753,067; 6,781,745; 6,788,452; 6,795,229; 6,806,995; 6,829,078;6,833,177; 6,850,355; 6,865,012; 6,870,662; 6,885,495; 6,906,779;6,930,818; 6,933,098; 6,947,202; 6,987,605; 7,046,228; 7,072,095;7,079,303; 7,141,279; 7,156,945; 7,205,355; 7,233,429; 7,261,920;7,271,947; 7,304,780; 7,307,778; 7,327,346; 7,347,957; 7,470,386;7,504,050; 7,580,180; 7,715,087; 7,767,126; 7,880,958; 8,002,948;8,154,790; 8,169,690; 8,441,432; 8,582,197; 8,891,156; 9,279,906;9,291,872; and 9,388,307; and U.S. Patent Applications Publication Nos.2003/0175480; 2003/0175481; 2003/0179437; 2003/0203101; 2013/0321744;2014/0050814; 2015/0085345; 2016/0059442; 2016/0004136; and2016/0059617;

(d) Methods for filling and sealing microcells; see for example U.S.Pat. Nos. 6,545,797; 6,751,008; 6,788,449; 6,831,770; 6,833,943;6,859,302; 6,867,898; 6,914,714; 6,972,893; 7,005,468; 7,046,228;7,052,571; 7,144,942; 7,166,182; 7,374,634; 7,385,751; 7,408,696;7,522,332; 7,557,981; 7,560,004; 7,564,614; 7,572,491; 7,616,374;7,684,108; 7,715,087; 7,715,088; 8,179,589; 8,361,356; 8,520,292;8,625,188; 8,830,561; 9,081,250; and 9,346,987; and U.S. PatentApplications Publication Nos. 2002/0188053; 2004/0120024; 2004/0219306;2006/0132897; 2006/0164715; 2006/0238489; 2007/0035497; 2007/0036919;2007/0243332; 2015/0098124; and 2016/0109780;

(e) Films and sub-assemblies containing electro-optic materials; see forexample U.S. Pat. Nos. 6,825,829; 6,982,178; 7,112,114; 7,158,282;7,236,292; 7,443,571; 7,513,813; 7,561,324; 7,636,191; 7,649,666;7,728,811; 7,729,039; 7,791,782; 7,839,564; 7,843,621; 7,843,624;8,034,209; 8,068,272; 8,077,381; 8,177,942; 8,390,301; 8,482,835;8,786,929; 8,830,553; 8,854,721; 9,075,280; and 9,238,340; and U.S.Patent Applications Publication Nos. 2007/0237962; 2009/0109519;2009/0168067; 2011/0164301; 2014/0115884; and 2014/0340738;

(f) Backplanes, adhesive layers and other auxiliary layers and methodsused in displays; see for example U.S. Pat. Nos. 7,116,318 and7,535,624;

(g) Color formation and color adjustment; see for example U.S. Pat. Nos.7,075,502 and 7,839,564;

(h) Methods for driving displays; see for example U.S. Pat. Nos.7,012,600 and 7,453,445;

(i) Applications of displays; see for example U.S. Pat. Nos. 7,312,784and 8,009,348; and

(j) Non-electrophoretic displays, as described in U.S. Pat. No.6,241,921 and U.S. Patent Application Publication No. 2015/0277160; andapplications of encapsulation and microcell technology other thandisplays; see for example U.S. Patent Application Publications Nos.2015/0005720 and 2016/0012710.

Referring now to FIG. 1, a quantum dot film 10 according to a firstembodiment of the present invention is illustrated. The quantum dot film10 may comprise a layer of light-transmissive polymeric material 11 thathas been embossed, for example, with a pattern of microcells. Thepattern may provide a plurality of microcells in a variety of geometricconfigurations, e.g. round, oval, cubic, hexagonal, etc. Within eachmicrocell is a preferably homogenous dispersion of quantum dots 18, 19in a fluid solvent 16, preferably a liquid. The dispersions are sealedwithin the microcells with a light-transmissive sealing layer 14 that ispreferably made from a curable material. The refractive index of thepolymeric material 11, solvent 16, and sealing layer 14 are preferablyclosely matched.

The layer of polymeric material provided with the plurality ofmicrocells, may include, but are not limited to, thermoplastic orthermoset materials or a precursor thereof, such as multifunctionalvinyls including, but not limited to, acrylates, methacrylates, allyls,vinylbenzenes, vinylethers, multifunctional epoxides and oligomers orpolymers thereof, and the like. Multifunctional acrylate and oligomersthereof are often used. A combination of a multifunctional epoxide and amultifunctional acrylate is also useful to achieve desirablephysico-mechanical properties of the microcells. A low Tg (glasstransition temperature) binder or crosslinkable oligomer impartingflexibility, such as urethane acrylate or polyester acrylate, may alsobe added to improve the flexure resistance of the film.

The layer of polymeric material comprising the plurality of microcellsprovides a flexible substrate, thereby enabling the use of variousprinting or coating techniques, some of which may be inexpensive, inorder to fill the microcells with the dispersions containing quantumdots. (Use of the word “printing” is intended to include all forms ofprinting and coating, including, but without limitation: pre-meteredcoatings such as patch die coating, slot or extrusion coating, slide orcascade coating, curtain coating; roll coating such as knife over rollcoating, forward and reverse roll coating; gravure coating; dip coating;spray coating; meniscus coating; spin coating; brush coating; air knifecoating; silk screen printing processes; electrostatic printingprocesses; thermal printing processes; ink jet printing processes;electrophoretic deposition (See U.S. Pat. No. 7,339,715); and othersimilar techniques.) Furthermore, because the resulting quantum dotfilms may be flexible, the films may be incorporated in flexibledisplays.

The polymeric materials may also comprise a polar oligomeric orpolymeric material. Such a polar oligomeric or polymeric material may beselected from the group consisting of oligomers or polymers having atleast one of the groups such as nitro (—NO2), hydroxyl (—OH), carboxyl(—COO), alkoxy (—OR wherein R is an alkyl group), halo (e.g., fluoro,chloro, bromo or iodo), cyano (—CN), sulfonate (—SO3) and the like. Theglass transition temperature of the polar polymer material is preferablybelow about 100° C. and more preferably below about 60° C. Specificexamples of suitable polar oligomeric or polymeric materials mayinclude, but are not limited to, polyhydroxy functionalized polyesteracrylates (such as BDE 1025, Bomar Specialties Co, Winsted, Conn.) oralkoxylated acrylates, such as ethoxylated nonyl phenol acrylate (e.g.,SR504, Sartomer Company), ethoxylated trimethylolpropane triacrylate(e.g., SR9035, Sartomer Company) or ethoxylated pentaerythritoltetraacrylate (e.g., SR494, from Sartomer Company).

Alternatively, the polymeric material may comprise (a) at least onedifunctional UV curable component, (b) at least one photoinitiator, and(c) at least one mold release agent. Suitable difunctional componentsmay have a molecular weight higher than about 200. Difunctionalacrylates are preferred and difunctional acrylates having a urethane orethoxylated backbone are particularly preferred. More specifically,suitable difunctional components may include, but are not limited to,diethylene glycol diacrylate (e.g., SR230 from Sartomer), triethyleneglycol diacrylate (e.g., SR272 from Sartomer), tetraethylene glycoldiacrylate (e.g., SR268 from Sartomer), polyethylene glycol diacrylate(e.g., SR295, SR344 or SR610 from Sartomer), polyethylene glycoldimethacrylate (e.g., SR603, SR644, SR252 or SR740 from Sartomer),ethoxylated bisphenol A diacrylate (e.g., CD9038, SR349, SR601 or SR602from Sartomer), ethoxylated bisphenol A dimethacrylate (e.g., CD540,CD542, SR101, SR150, SR348, SR480 or SR541 from Sartomer), and urethanediacrylate (e.g., CN959, CN961, CN964, CN965, CN980 or CN981 fromSartomer; Ebecryl 230, Ebecryl 270, Ebecryl 8402, Ebecryl 8804, Ebecryl8807 or Ebecryl 8808 from Cytec). Suitable photoinitiators may include,but are not limited to, bis-acyl-phosphine oxide,2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone,2,4,6-trimethylbenzoyl diphenyl phosphine oxide,2-isopropyl-9H-thioxanthen-9-one, 4-benzoyl-4′-methyldiphenylsulphideand 1-hydroxy-cyclohexyl-phenyl-ketone,2-hydroxy-2-methyl-1-phenyl-propan-1-one,1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one,2,2-dimethoxy-1,2-diphenylethan-1-one or2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one. Suitable moldrelease agents may include, but are not limited to, organomodifiedsilicone copolymers such as silicone acrylates (e.g., Ebecryl 1360 orEbecryl 350 from Cytec), silicone polyethers (e.g., Silwet 7200, Silwet7210, Silwet 7220, Silwet 7230, Silwet 7500, Silwet 7600 or Silwet 7607from Momentive). The composition may further optionally comprise one ormore of the following components, a co-initiator, monofunctional UVcurable component, multifunctional UV curable component or stabilizer.

The preferred method of providing the polymeric material with microcellsis by applying a pattern of microstructures on one surface of thepolymeric material, such as the methods described in U.S. Pat. No.6,930,818, the content of which is incorporated herein by reference inits entirety. For example, a drum having a three-dimensional pattern onits outer surface may be used to emboss a continuous sheet of polymericmaterial in a roll-to-roll process. The pattern on the surface of thedrum may be in the form of a plurality of microposts, for example.

The quantum dot material in the dispersions may comprise one or moreparticulate material having one or more particle sizes. In a preferredembodiment of the present invention, the quantum dot material emit bothgreen and red light when exposed to blue light. The quantum dot materialmay include, but is not limited to, CdSe core/shell luminescentnanocrystals, such as CdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS orCdTe/ZnS nanocrystals.

The quantum dot material is preferably provided in the form ofnanoparticles having diameters substantially less than the wavelengthsof visible light. The term “diameter” is used herein to include what isusually known as the “equivalent diameter” of a non-spherical particle.The nanoparticles used in the present invention need not be spherical oreven essentially spherical. Variations in the properties of thenanoparticle displays can be achieved using non-spherical and compositeparticles, for example particles in which a core of one material issurrounded by a shell of a different material, and the present inventionextends to nanoparticle displays and assemblies using such non-sphericaland/or composite particles.

The non-spherical nanoparticles used in the present invention (whichwill typically be formed in whole or part from electrically conductivematerials) may have a wide variety of shapes. For example, suchparticles may have the form of ellipsoids, which may have all threeprincipal axes of differing lengths, or may be oblate or prolateellipsoids of revolution. The non-spherical nanoparticles mayalternatively be laminar in form, the term “laminar” being used hereinin a broad sense to indicate bodies in which the maximum dimension alongone axis is substantially less than the maximum dimension along each ofthe other two axes; thus, such laminar nanoparticles may have a formsimilar to the tabular silver halide grains well known in photographicfilms. The non-spherical nanoparticles may also have the form of frustaof pyramids or cones, or of elongate rods. Finally, the nanoparticlesmay be irregular in shape.

Composite (core/shell) nanoparticles used in the present invention mayhave any of the forms discussed in the preceding paragraph, and willtypically comprise an electrically conductive shell around an insulatingcore, or an electrically insulating shell around a conductive core. Aninsulating core may be formed from, for example, silicon, titania, zincoxide, aluminum silicates, various inorganic salts, or sulfur. Like thesimple nanoparticles discussed above, the composite nanoparticles may besubjected to surface modification, for example to control the degree towhich particles adhere to one another or to any surface with which theycome into contact. One preferred type of surface modification isattachment of polymers to the surfaces of the nanoparticles.

As previously noted, one of the aspects of the various embodiments ofthe present invention is that the quantum dots may remain in the form ofa dispersion when sealed in the microcells. The dispersion, as describedherein, used to fill the microcells may preferably comprise, withincreasing preference in the order given, not less than 0.01, 0.02,0.04, 0.06, 0.08, 0.1, 0.2, 0.3, 0.4, 0.5% wt quantum dots andindependently preferably is, with increasing preference in the ordergiven, not more than, at least for economy, 0.6, 0.7, 0.8, 0.9, 1.0,2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10% wt quantum dots.

The solvent may be a fluid, preferably a liquid that is clear andcolorless, and more preferably a fluid with a refractive index thatmatches the refractive index of the light transmissive microcells and/orsealing layer. Examples of suitable solvents include hydrocarbons suchas hexane, isopar, decahydronaphthalene (DECALIN),5-ethylidene-2-norbornene, fatty oils, paraffin oil, silicon fluids,aromatic hydrocarbons such as toluene, xylene, phenylxylylethane,dodecylbenzene or alkylnaphthalene, halogenated solvents such aschloroform, perfluorodecalin, perfluorotoluene, perfluoroxylene,dichlorobenzotrifluoride, 3,4,5-trichlorobenzotri fluoride,chloropentafluoro-benzene, dichlorononane or pentachlorobenzene, andperfluorinated solvents such as FC-43, FC-70 or FC-5060 from 3M Company,St. Paul Minn., low molecular weight halogen containing polymers such aspoly(perfluoropropylene oxide) from TCI America, Portland, Oreg.,poly(chlorotrifluoro-ethylene) such as Halocarbon Oils from HalocarbonProduct Corp., River Edge, N.J., perfluoropolyalkylether such as Galdenfrom Ausimont or Krytox Oils and Greases K-Fluid Series from DuPont,Delaware, polydimethylsiloxane based silicone oil from Dow-corning(DC-200).

The layer of sealing material for sealing the microcells may be appliedusing various techniques. For example, sealing may be accomplished bydispersing a thermoplastic or thermoset precursor in the dispersionfluid, wherein the thermoplastic or thermoset precursor is immiscible inthe dispersion fluid and has a specific gravity lower than that of thedisplay fluids. After filling the microcells with theprecursor/dispersion mixture, the precursor phase separates from thedispersion and forms a supernatant layer which is then hardened or curedby solvent evaporation, interfacial reaction, moisture, heat orradiation. Specific examples of thermoplastics or thermosets andprecursors thereof may include materials such as monofunctionalacrylates, monofunctional methacrylates, multifunctional acrylates,multifunctional methacrylates, polyvinyl alcohol, polyacrylic acid,cellulose, gelatin or the like. Additives such as a polymeric binder orthickener, photoinitiator, catalyst, vulcanizer, filler, colorant orsurfactant may be added to the sealing composition to improve thephysico-mechanical properties and the optical properties of the display.

In another more preferably method, sealing may be accomplished byapplying a sealing layer comprising an aqueous composition over thedispersion-filled microcells that is subsequently dried. In an aqueouscomposition, the sealing material may be an aqueous solution of a watersoluble polymer. Examples of suitable water soluble polymers or watersoluble polymer precursors may include, but are not limited to,polyvinyl alcohol; polyethylene glycol, its copolymers withpolypropylene glycol, and its derivatives, such as PEG-PPG-PEG, PPG-PEG,PPG-PEG-PPG; poly(vinylpyrolidone) and its copolymers such aspoly(vinylpyrrolidone)/vinyl acetate (PVP/VA); polysaccharides such ascellulose and its derivatives, poly(glucosamine), dextran, guar gum, andstarch; gelatin; melamine-formaldehyde; poly(acrylic acid), its saltforms, and its copolymers; poly(methacrylic acid), its salt forms, andits copolymers; poly(maleic acid), its salt forms, and its copolymers;poly(2-dimethylaminoethyl methacrylate); poly(2-ethyl-2-oxazoline);poly(2-vinylpyridine); poly(allylamine); polyacrylamide;polyethylenimine; polymethacrylamide; poly(sodium styrene sulfonate);cationic polymer functionalized with quaternary ammonium groups, such aspoly(2-methacryloxyethyltrimethylammonium bromide), poly(allylaminehydrochloride). The sealing material may also include a waterdispersible polymer dispersed in water. Examples of suitable polymerwater dispersions may include polyurethane water dispersions and latexwater dispersions. Suitable latexes in the water dispersions includepolyacrylate, polyvinyl acetate and its copolymers such as ethylenevinyl acetate, and polystyrene copolymers such as polystyrene butadieneand polystyrene/acrylate.

Referring again to FIG. 1, the quantum dot film 10 may optionallyinclude a single or, more preferably, double release sheet 12, 13. Therelease sheets 12, 13 are preferably applied after the microcells arecured, filled, and sealed, such that the sheet of polymeric material issandwiched between two adhesive layers, one or both of the adhesivelayers being covered by a release sheet. By providing the polymericsheets with one or more release sheets, the quantum dot film may be moreeasily used in a lamination process for assembling an electro-opticdisplay.

For example, referring now to the embodiment of FIG. 2, an electro-opticdisplay 20 may include a plurality of laminated layers, wherein one ofthe layers is a quantum dot film 23, as previously described. Thequantum dot film 23 may be laminated between a back light unit 22 and acolor filter 24. The back light unit 22 may optionally be laminated to areflective substrate 21 in order to direct light through the quantum dotfilm 23. The back light unit 22 preferably includes one or more blueLEDs and a light-guide plate configured to evenly distribute the lightacross the display 20.

A layer of shuttering media 26 may be laminated to the color filter 24,such that the color filter 24 is between the quantum dot film 23 and theshuttering media 26. The shuttering media may include any electro-opticmedia that is capable of being switched between a generallylight-missive state and an opaque state. Blue light emitted from theback light unit 22 will pass through the quantum dot film 23, which willconvert a portion of the blue light to red and green light. The red,green, and blue light will enter the color filter 24 and filtereddepending on the section of the color filter through which the filterpasses. For example, the “R” portion will absorb the green and bluelight, allowing the red light to pass, the “G” portion will absorb thered and blue light, allowing the green light to pass, and the “B”portion will absorb the red and green light, allowing the blue light topass. The shuttering media above each section of the color filter 24 maybe independently switched to allow a combination and/or selection ofred, green, and blue light to pass and ultimately emitted by thedisplay. Types of electro-optic media that may be used as a shutteringlayer include, but are not limited to, liquid crystals, electro-chromicmaterials, and a di-electrophoretic dispersion.

In order to control the shuttering media, a series of light-transmissiveelectrodes 25 may be provided between the layer of shuttering media 26and the color filter 24, and a continuous, light-transmissive frontelectrode 27 may be applied on the opposing side of the layer ofshuttering media 26. The light-transmissive electrodes may be a thinmetal or metal oxide layer of, for example, aluminum or ITO, or may be aconductive polymer. Finally, a light-transmissive protective layer 28may be provided as an outer viewing surface of the display 20.

As would be appreciated by those of skill in the art, the embodimentillustrated in FIG. 2 may include more or less layers that thoseillustrated. For example additional adhesive layers may be incorporatedbetween each of the layers. Alternatively, the color filter layer 24 andthe plurality light-transmissive electrodes 25 may be combined into onelayer, such that the electrodes are made from a light-transmissivecolored conductive material. In yet another variation, the two electrodelayers 25 and 27 may be reversed, such that the continuous electrodelayer 27 is sandwiched between the shuttering layer 26 and the colorfilter 24 and the plurality of light-transmissive electrodes 25 islocated adjacent the front protective layer 28.

All of the contents of the publications disclosed above are incorporatedby reference herein.

While the present invention has been described with reference to thespecific embodiments thereof, it should be understood by those skilledin the art that various changes may be made and equivalents may besubstituted without departing from the true spirit and scope of theinvention. In addition, many modifications may be made to adapt aparticular situation, materials, compositions, processes, process stepor steps, to the objective and scope of the present invention. All suchmodifications are intended to be within the scope of the claims appendedhereto.

I claim:
 1. A quantum dot film comprising a plurality of sealedmicrocells, the microcells being formed within a layer of polymericmaterial and sealed with a sealing material, and the microcellscontaining a dispersion comprising a solvent and a plurality of quantumdots, wherein the sealing material is selected from the group consistingof monofunctional acrylates; monofunctional methacrylates;multifunctional acrylates; multifunctional methacrylates; polyvinylalcohol; polyacrylic acid; gelatin; polyethylene glycol, copolymers ofpolyethylene glycol and polypropylene glycol, and derivatives thereof;poly(vinylpyrolidone) and copolymers thereof; polysaccharides andderivatives thereof; melamine-formaldehyde; poly(acrylic acid) and saltforms and copolymers thereof; poly(methacrylic acid) and salt forms andcopolymers thereof; poly(maleic acid) and salt forms and copolymersthereof; poly(2-dimethylaminoethyl methacrylate);poly(2-ethyl-2-oxazoline); poly(2-vinylpyridine); poly(allylamine);polyacrylamide; polyethylenimine; polymethacrylamide; poly(sodiumstyrene sulfonate); cationic polymers functionalized with quaternaryammonium groups; polyurethane water dispersions; and latex waterdispersions.
 2. The quantum dot film of claim 1, wherein the polymericmaterial is selected from the group consisting of a thermoplastic and athermoset.
 3. The quantum dot film of claim 1, wherein the sealingmaterial is light transmissive.
 4. The quantum dot film of claim 1,wherein the solvent comprises a liquid.
 5. The quantum dot film of claim1, wherein the dispersion comprises 0.01 to 10% wt. quantum dots.
 6. Thequantum dot film of claim 1, wherein the quantum dots comprisenanocrystals selected from the group consisting of CdSe/ZnS, InP/ZnS,PbSe/PbS, CdSe/CdS, CdTe/CdS and CdTe/ZnS.
 7. An electro-optic displaycomprising a quantum dot film according to claim
 1. 8. The electro-opticdisplay of claim 7 further comprising a light-emitting layer and a colorfilter layer, wherein the quantum dot film is disposed between thelight-emitting layer and the color filter layer.
 9. The electro-opticdisplay of claim 8, further comprising a layer of shuttering mediaselected from the group consisting of liquid crystal, adi-electrophoretic dispersion, and electrochromic material.
 10. A methodof making a quantum dot film comprising: providing a layer of polymericmaterial having a plurality of open microcells; filling the plurality ofopen microcells with a dispersion comprising a solvent and plurality ofquantum dots; and sealing the microcells, wherein the sealing materialis selected from the group consisting of monofunctional acrylates;monofunctional methacrylates; multifunctional acrylates; multifunctionalmethacrylates; polyvinyl alcohol; polyacrylic acid; gelatin;polyethylene glycol, copolymers of polyethylene glycol and polypropyleneglycol, and derivatives thereof; poly(vinylpyrolidone) and copolymersthereof; polysaccharides and derivatives thereof; melamine-formaldehyde;poly(acrylic acid) and salt forms and copolymers thereof;poly(methacrylic acid) and salt forms and copolymers thereof;poly(maleic acid) and salt forms and copolymers thereof;poly(2-dimethylaminoethyl methacrylate); poly(2-ethyl-2-oxazoline);poly(2-vinylpyridine); poly(allylamine); polyacrylamide;polyethylenimine; polymethacrylamide; poly(sodium styrene sulfonate);cationic polymers functionalized with quaternary ammonium groups;polyurethane water dispersions; and latex water dispersions.
 11. Themethod of claim 10, wherein the providing step comprises embossing theplurality of open microcells into the layer of polymeric material. 12.The method of claim 10, wherein the dispersion further comprises acurable compound and the sealing step comprises curing the curablecompound to form a sealing layer and contain the solvent and pluralityof quantum dots within the sealed microcells.
 13. A quantum dot filmcomprising a plurality of sealed microcells, the microcells being formedwithin a layer of polymeric material and sealed with a sealing material,and the microcells containing a dispersion comprising a solvent and aplurality of quantum dots, wherein the quantum dots comprisenanocrystals selected from the group consisting of CdSe/ZnS, InP/ZnS,PbSe/PbS, CdSe/CdS, CdTe/CdS and CdTe/ZnS.
 14. The quantum dot film ofclaim 13, wherein the polymeric material is selected from the groupconsisting of a thermoplastic and a thermoset.
 15. The quantum dot filmof claim 13, wherein the sealing material is selected from the groupconsisting of monofunctional acrylates; monofunctional methacrylates;multifunctional acrylates; multifunctional methacrylates; polyvinylalcohol; polyacrylic acid; gelatin; polyethylene glycol, copolymers ofpolyethylene glycol and polypropylene glycol, and derivatives thereof;poly(vinylpyrolidone) and copolymers thereof; polysaccharides andderivatives thereof; melamine-formaldehyde; poly(acrylic acid) and saltforms and copolymers thereof; poly(methacrylic acid) and salt forms andcopolymers thereof; poly(maleic acid) and salt forms and copolymersthereof; poly(2-dimethylaminoethyl methacrylate);poly(2-ethyl-2-oxazoline); poly(2-vinylpyridine); poly(allylamine);polyacrylamide; polyethylenimine; polymethacrylamide; poly(sodiumstyrene sulfonate); cationic polymers functionalized with quaternaryammonium groups; polyurethane water dispersions; and latex waterdispersions.
 16. The quantum dot film of claim 15, wherein the sealingmaterial is light transmissive.
 17. The quantum dot film of claim 13,wherein the solvent comprises a liquid.
 18. The quantum dot film ofclaim 13, wherein the dispersion comprises 0.01 to 10% wt. quantum dots.19. An electro-optic display comprising a quantum dot film according toclaim
 13. 20. The electro-optic display of claim 19 further comprising alight-emitting layer and a color filter layer, wherein the quantum dotfilm is disposed between the light-emitting layer and the color filterlayer.
 21. The electro-optic display of claim 20, further comprising alayer of shuttering media selected from the group consisting of liquidcrystal, a di-electrophoretic dispersion, and electrochromic material.22. A method of making a quantum dot film comprising: providing a layerof polymeric material having a plurality of open microcells; filling theplurality of open microcells with a dispersion comprising a solvent andplurality of quantum dots; and sealing the microcells, wherein thequantum dots comprise nanocrystals selected from the group consisting ofCdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS and CdTe/ZnS.
 23. Themethod of claim 22, wherein the providing step comprises embossing theplurality of open microcells into the layer of polymeric material. 24.The method of claim 22, wherein the dispersion further comprises acurable compound and the sealing step comprises curing the curablecompound to form a sealing layer and contain the solvent and pluralityof quantum dots within the sealed microcells.